In French patent application No. 89 13 488 filed 16 Oct. 1989, the Applicant describes a metal-clad electricity line and a method of manufacturing it.
According to that document, each phase conductor is disposed in a coaxial tubular envelope made of aluminum, and each aluminum envelope is surrounded by a gastight coaxial envelope that is filled with a gas having good dielectric properties. The three gastight envelopes of a three-phase line are placed inside an underground gallery by means of appropriate supports.
It is already mentioned in that document that the three aluminum envelopes of a three-phase electricity line could be placed in a common gastight envelope that is buried or is placed inside an underground gallery.
The present patent application relates to implementing said solution, and thus relates to the various component elements of the metal-clad line and also to a method of installing it on site.